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Microbio - PostMidterm A SGU 2013
Microbio - PostMidterm A SGU 2013
72
Microbiology
Professional
05/06/2013

Additional Microbiology Flashcards

 


 

Cards

Term
HIV 1 and HIV 2 probably came from what animals ?
Definition
HIV-1 from chimpanzees
HIV-2 from sooty mangabey
Term
What subtype of HIV-1 is in USA ?
Definition
Subtype B
Term
What is the first pathogenic human retrovirus ?
Definition
Human T-cell leukemia virus
Term
What sub-family do HIV-1 and HIV-2 belong in ?
Definition
Lentivirinae
Term
Reverse transcriptase is what ?
Definition
RNA dependent DNA polymerase

Converts ss HIV RNA to ds HIV DNA
Term
GP120 and GP41 make up ?
Definition
GP160
Term
What enzyme helps HIV insert its DNA into host cell's DNA ?
Definition
HIV integrase
Term
What does HIV need to bind CD4 and co-receptors, allowing them to move on and infect other cells ?
Definition
HIV glycoproteins
Term
2 reasons HIV is hard to stop ?
Definition
1) Reverse transcriptase has low fidelity so can make a lot of errors, and HIV keeps evlovling

2) Heterodimers increase variability of HIV genomes so cell can be co-infected by more than 1 HIV protein
Term
HIV enters the body via what cells ?
Definition
Infected macrophages
Term
HIV encephalopathy is due to ?
Definition
Synctial fusion of HIV-infected macrophages and macroglia
Term
HIV therapy starts when CD4 + cells fall below ?
Definition
350 cells / ul
Term
Seroconversion means what ?
Definition
When you can detect antibodies
Term
What is window period for HIV ?
Definition
Negative HIV test (primary infection to seroconversion)
Viral load very high, increase high transmission risk
Term
Final stage of HIV infection ?
Definition
AIDS
Term
Progression of AIDS ?
Definition
A S L L O

1) Acute infection
2) Strong anti-HIV immune defense
3) Latent resorvior
4) Loss of CD4+ cells and loss of immune response
5) Onset of AIDS
Term
What bacteria causes bacterial pneumonia in AIDS pts ?
Definition
Strep Pneumoniae
Term
AIDS pts can get Mycobacterium Avium Complex under what circumstances ?
Definition
Advanced HIV infection and a CD4 lymphocyte count < 50

MAC presents as night sweats, weight loss, abdominal pain, anemia, etc...
Term
What is leading cause of death for those living with AIDS ?
Definition
TB
Term
Infections associated with AIDS ?
Definition
Bacterial Pneumonia
MAC
TB
Salmoneliosis
Bacillary Angiomatosis
Viral Hepatitis (Hep B and Hep C)
CMV
HHV-1, HHV-2
HPV
Progressive Multifocal Leukoencephalopathy (PML) - caused by JC virus

A lot of other infections
Term
PML is a serious brain infection in AIDS pts. caused by what ?
Definition
JC virus
Term
Cryptosporidium Parvum becomes self-limiting in individuals with CD4 counts greater than ?
Definition
200
Term
Most common microorganism that causes infectious pharyngitis ?
Definition
Strep. Pyogenes
Term
Lower Resp. tract (37 degrees celsius) has no normal flora why ?
Definition
It is usually sterile

Particles should be less than 5 microns to get through.
Nonciliated epithelium
IgG and IgA
Term
What droplet tends to remain suspended in the air the longest and can cause infection ?
Definition
Dried droplet nuclei
Term
Another name for professional invader in a respiratory infection ?
Definition
Frank pathogen
Term
3 Diseases of lower respiratory tract infections ?
Definition
Bronchitis
Bronchiolitis
Pneumonias
Term
Bordet-Gengou growth media can culture what organism ?
Definition
Bordetella Pertussis
Term
Tinsdale Agar can culture what organism ?
Definition
C. Diptheriae
Term
T or F : Some resp. viruses do not exert their main pathology in resp. tract ?
Definition
True

They are transported by respiratory droplets
Term
Influenza virus has what type of nucleic acid ?
Definition
Segmented RNA
Term
Adenoviruses have what type of nucleic acid ?
Definition
Linear ds DNA (Class 1)
Term
Some adenoviral components that interfere with host immune response ?
Definition
E1A
E1B
E3
E4
VA RNAs
Term
Adenovirus Pathogenesis ?
Definition
Fiber protein : enables attachment to host cell receptor

Receptor varies with viral serotype

Penton base has toxic activity
(inhibition of cellular mRNA synthesis, cell rounding, tissue damage)
Term
What virus causes phayngitis and conjunctivitis ?
Definition
Adenovirus
Term
Antigenic drift allows rhinoviruses to have ?
Definition
High number of viral serotypes
Term
What virus can cause common cold and SARS ?
Definition
Coronaviruses

ss (+) RNA
enveloped
helical nucleocapsid
have "spike" proteins or peplomers

Transmission mostly via droplets, fecal/oral also possible

Replicate in ** ciliated nasal epithelium **
Term
Etiologic agent for SARS ?
Definition
New Coronavirus (SARS-CoV)
Term
What viruses cause laryngotrachobronchitis and bronchitis ?
Definition
HPIV (Human Parainfluenza viruses)

Family is Paramyxoviridae
Divided into 2 sub-famalies

Enveloped
Glycoprotein with HN (Hemagglutinin-Neuraminidase) activity

Fusion Factor (F) protein involved in viral entry, and against which antibodies can neutralize virus
Term
Which HPIV virus causes Croup (or laryngotrachobronchitis) ?
Definition
HPIV-1
Term
Paramyoxovirinae subfamily of viruses evades immune response how ?
Definition
Via V proteins (fusion proteins)

Which prevent apoptosis, prevent interferon synthesis, etc...
Term
RSV belongs to what virus subfamily ?
Definition
Pneumovirinae
Term
Pathogenesis of RSV ?
Definition
1) Entry is via epithelia nose and eye

2) F & G proteins mediate attachment ; F mediates membrane fusion

3) Primary site of replication is nasopharyngeal epithelium
Direct CPE is loss of function
Term
Do not give what as trt of RSV ?
Definition
Heat-killed vaccine, b/c it enhances RSV disease...may due to CD8 T cells (immunopathology)
Term
Based on symptoms, how to differentiate b/w cold and flu ?
Definition
Flu has fever, headache, vomiting/diarrhea, and severe malaise
Term
3 types of influenza virus ?
Definition
A (found in birds like ducks, only one classified by HN system, can cause epidemic and pandemic)

B (also in seals, two lineages: Victoria-like and Yamagata-like)

C (no epidemic or pandemic)
Term
Influenza / flu is a zoonotic disease ?
Definition
Yes
Term
Antigenic Shift and Influenza ?
Definition
Is a sudden rearrangement of 8 genetic subunits of influenza virus, usually due to co-infection of two diff. influenza A strains.

Only affects influenza A
Term
How do the following Anti-Flu drugs work ?
Definition
Amantadine and Rimantadine - Inhibit uncoating of Influenza A only
Target M2 protein

Zanamivir and Oseltamvir (Tamiflu) - Inhibit neuraminidase by blocking its release, only works on influenza A and B
Term
What does not work against flu / influenza ?
Definition
Post-exposure trt

Excessive use of antimicrobials builds up drug-resistance
Term
How to distinguish Strep. Pyogenes from all other Beta-hemolytic streptococci ?
Definition
Strep. Pyogenes is Bacitracin sensitive
Term
How to distinguish Strep. Pneumoniae from all other alpah-hemolytic Strep such as Strep. Viridans ?
Definition
Strep. Pneumoniae is optochin sensitive
Term
Pneumolysin is one of the virulence factors of what bacteria ?
Definition
Strep. Pneumoniae

Is a pore-former
inhibits ciliated epithelial activity
decreases PMN effectiveness
etc...
Term
What test is used for determining toxicity of Cornyebacterium Diptheriae ?
Definition
Elek test

Lines of precipitin on plate indicates toxigenic
Term
How is diptheria exotoxin produced ?
Definition
Via lysogenic bacteriophage conversion
Term
What bacteria most common cause of epiglottitis ?
Definition
Hemophilus influenzae (is a Gram - rod)

**Does not cause influenza**
Term
Pathogenesis of H. Influenzae ?
Definition
Pili
Non-pilus adhesins
LPS
PRP (Poplyribose Ribitol Phosphate) - antiphagocytic capsule made of this
Term
Culture of H. Influenzae requires what ?
Definition
Chocolate agar with X factor (hemin) and V factor (NAD)
Term
What bacteria causes whooping cough (chronic bronchitis) ?
Definition
BOrdetella Pertussis
Term
Why not use cotton swab or throat swab to culture Bordetella Pertussis ?
Definition
B/c the bacteria is very susceptible to drying

But can culture with nasopharyngeal swab or secretions
Term
Characteristics of Klebsiella Pneumoniae ?
Definition
Non-spore forming Gram - rod (bacillus)

**Necrotizing Pneumonia**

Bronchopneumonia, lung abscesses
Two iron uptake systems: aerobactin and enterochelin (are siderophores)
"Red currant jelly" sputum
Term
Characteristics of Legionella Pneumophila ?
Definition
Causes Legionnaire's disease (pneumonia) and Pontiac fever (self-limiting)

Gram - rod, motile, non-spore forming
80% of infections due to serogroup 1

Cannot gram stain b/c bacteria does not take up the counter stain
Detect via serology for agglutination or fluorescent antibodies, or with ELISA
Term
What bacteria is a Gram - rod, non-hemolytic, ** smells like grapes ** , is found in fresh water and sea water, stains green on media due to pyocyanin and fluorescein pigments, whose most common infection is otitis externa (swimmer's ear), and is dangerous for people who are burn victims or have cystic fibrosis ?
Definition
Pseudomonas
Term
What two bacteria can cause necrotizing pneumonia ?
Definition
Klebsiella Pneumoniae and Pseudomonas
Term
Two methods to culture M. tuberculosis ?
Definition
Lowenstein-Jensen agar
Oleic acid - albumin broth
Term
What is a positive result for TB on Tuberculin test ?
Definition
Induration > 10 mm diameter
Term
Two ways to prevent TB ?
Definition
Prophylactic antimycotics

BCG (Bacillus Calmette-Guerin) vaccine - attenuated M. bovis strain
Term
Know TB first line and second line trts

and

TB Drug Resistance categories
Definition
Term
Two clinically significant varieties of Histoplasma Capsulatum (causes Histoplasmosis) ?
Definition
H. capsulatum var capsulatum

H. capsulatum var duboisii
Term
Most virulent of all human mycotic pathogens ?
Definition
Coccidioides species
Term
Most common fungal infection seen in AIDS patients ?
Definition
Cryptococcosis
Term
Two forms of Aspergillosis ?
Definition
1) Allergic

2) Invasive: hyphae invade tissue

Gan get "fungal ball" (Aspergilloma)

Can get acute pneumonia in severly immunocompromised persons (neutropenia)
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